Re: How to crash postgres using savepoints

Tom Lane wrote:
> Joseph Shraibman <jks@selectacast.net> writes:
>> See example below. At the very least the documentation needs to tell 
>> users that savepoints use shared memory, and the cofusing HINT string 
>> needs to be changed to something more useful.
> 
> Which part of "You may need to increase max_locks_per_transaction" do
> you find confusing?  If you actually need tens of thousands of nested
> savepoints then this is accurate advice.

Because there is nothing anywhere that indicates that a savepoint uses a 
lock.  When I got the message the first time I was very confused and had 
nowhere to look to figure out what the real problem was.  A more helpful 
message would be "You may need to increase max_locks_per_transaction, or 
release your savepoints more often"

Why does a savepoint need shared memory anyway, if it is only useful 
inside the transaction it was created in?